Draw a GraphicsPath in a PDF - itext

Question

I am trying to create a PDF based on some vector art I have in my C# application. I have two major problems when I try to map the points and types from a GraphicsPath.
Some paths are just plain missing.
When a sub path is an internal boundary I need to indicate that somehow. ie, the circle in the letter d is filled in.
I'm referencing iTextSharp 5.5.2 on NuGet. I'm only using AddString here because I want an easy way to demonstrate creating a complex path in this example. For my need I won't be using a path to place text in the PDF.
using iTextSharp.text;
using iTextSharp.text.pdf;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace PdfGen
{
class StackQuestion
{
public static void Main()
{
string filename = #"d:\itext.pdf";
using (var doc = new Document())
using (var fs = new FileStream(filename, FileMode.Create))
{
var writer = PdfWriter.GetInstance(doc, fs);
doc.Open();
writer.DirectContent.SetColorFill(BaseColor.BLACK);
var path = new GraphicsPath(FillMode.Winding);
path.AddString("Hello World", FontFamily.GenericSerif,
(int)FontStyle.Regular, 25f, RectangleF.Empty,
StringFormat.GenericDefault);
AddPath(path, writer.DirectContent);
doc.Close();
}
System.Diagnostics.Process.Start(filename);
}
static void AddPath(GraphicsPath path, PdfContentByte to)
{
var view = to.PdfDocument.PageSize;
path.FillMode = System.Drawing.Drawing2D.FillMode.Winding;
var d = path.PathData;
for (int i = 0; i < d.Points.Length && i < d.Types.Length; i++)
{
var t = (PathPointType)d.Types[i];
var p = Fix(d.Points[i], view);
if (Match(t, PathPointType.Bezier))
{
var p2 = Fix(d.Points[++i], view);
if (d.Types.Length > i + 1 &&
Match((PathPointType)d.Types[i + 1],
PathPointType.Bezier3))
{
var p3 = Fix(d.Points[++i], view);
to.CurveTo(p.X, p.Y, p2.X, p2.Y, p3.X, p3.Y);
}
else
{
to.CurveTo(p.X, p.Y, p2.X, p2.Y);
}
}
if (Match(t, PathPointType.Line))
{
to.LineTo(p.X, p.Y);
}
if (Match(t, PathPointType.CloseSubpath))
{
to.ClosePath();
to.EoFill();
}
if (t == PathPointType.Start)
{
to.NewPath();
to.MoveTo(p.X, p.Y);
}
}
}
static bool Match(PathPointType type, PathPointType match)
{
return (type & match) == match;
}
static System.Drawing.PointF Fix(System.Drawing.PointF pt,
iTextSharp.text.Rectangle view)
{
return new System.Drawing.PointF(pt.X, view.Height - pt.Y);
}
}
}

Answer 1

I'm posting an answer to myself in case anyone else is in need of a simple function to plot out a GraphicsPath in iTextSharp. I had two problems with my sample code in the question:
as mkl pointed out I was trying to fill too often
I failed to notice that PathPointType.Line is a valid mask in PathPointType.Bezier so the code placing a line back to the origin after a curve.
Updatd Code:
using iTextSharp.text;
using iTextSharp.text.pdf;
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
namespace PdfGen
{
class StackQuestion
{
public static void Main()
{
string filename = #"d:\itext.pdf";
using (var doc = new Document())
using (var fs = new FileStream(filename, FileMode.Create))
{
var writer = PdfWriter.GetInstance(doc, fs);
doc.Open();
writer.DirectContent.SetColorFill(BaseColor.BLACK);
var path = new GraphicsPath(FillMode.Winding);
path.AddString("Hello World", FontFamily.GenericSansSerif,
(int)FontStyle.Regular, 90f, PointF.Empty,
StringFormat.GenericDefault);
AddPath(path, writer.DirectContent);
writer.DirectContent.EoFill();
doc.Close();
}
System.Diagnostics.Process.Start(filename);
}
static void AddPath(GraphicsPath path, PdfContentByte to)
{
var view = to.PdfDocument.PageSize;
var d = path.PathData;
to.NewPath();
PointF? start = null;
for (int i = 0; i < d.Points.Length && i < d.Types.Length; i++)
{
var t = (PathPointType)d.Types[i];
var p = Fix(d.Points[i], view);
if (Match(t, PathPointType.Bezier))
{
var p2 = Fix(d.Points[++i], view);
if (d.Types.Length > i + 1 &&
Match((PathPointType)d.Types[i + 1],
PathPointType.Bezier))
{
var p3 = Fix(d.Points[++i], view);
to.CurveTo(p.X, p.Y, p2.X, p2.Y, p3.X, p3.Y);
}
else
{
to.CurveTo(p.X, p.Y, p2.X, p2.Y);
}
}
else if (Match(t, PathPointType.Line))
{
to.LineTo(p.X, p.Y);
}
if (Match(t, PathPointType.CloseSubpath))
{
if (start != null)
to.LineTo(start.Value.X, start.Value.Y);
start = null;
to.ClosePath();
}
if (t == PathPointType.Start)
{
if (start != null)
to.LineTo(start.Value.X, start.Value.Y);
start = p;
to.MoveTo(p.X, p.Y);
}
}
}
static bool Match(PathPointType type, PathPointType match)
{
return (type & match) == match;
}
static System.Drawing.PointF Fix(System.Drawing.PointF pt,
iTextSharp.text.Rectangle view)
{
return new System.Drawing.PointF(pt.X, view.Height - pt.Y);
}
}
}